x86: fully honor "nolapic"

Impact: widen the effect of the 'nolapic' boot parameter

"nolapic" should not only suppress SMP and use of the LAPIC, but it
also ought to have the effect of disabling all IO-APIC related activity
as well as PCI MSI and HT-IRQs.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 13 insertions, 1 deletions

diff --git a/arch/x86/kernel/apic.c b/arch/x86/kernel/apic.c
index 0f830e4f5675..c3dd64fabcf3 100644
--- a/arch/x86/kernel/apic.c
+++ b/arch/x86/kernel/apic.c
@@ -1126,6 +1126,11 @@ void __cpuinit setup_local_APIC(void)
         unsigned int value;
         int i, j;
 
+        if (disable_apic) {
+                disable_ioapic_setup();
+                return;
+        }
+
 #ifdef CONFIG_X86_32
         /* Pound the ESR really hard over the head with a big hammer - mbligh */
         if (lapic_is_integrated() && esr_disable) {
@@ -1566,11 +1571,11 @@ int apic_version[MAX_APICS];
 
 int __init APIC_init_uniprocessor(void)
 {
-#ifdef CONFIG_X86_64
         if (disable_apic) {
                 pr_info("Apic disabled\n");
                 return -1;
         }
+#ifdef CONFIG_X86_64
         if (!cpu_has_apic) {
                 disable_apic = 1;
                 pr_info("Apic disabled by BIOS\n");
diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
index 1c4a1302536c..40747e58f305 100644
--- a/arch/x86/kernel/io_apic.c
+++ b/arch/x86/kernel/io_apic.c
@@ -3258,6 +3258,9 @@ static int msi_compose_msg(struct pci_dev *pdev, unsigned int irq, struct msi_ms
         int err;
         unsigned dest;
 
+        if (disable_apic)
+                return -ENXIO;
+
         cfg = irq_cfg(irq);
         err = assign_irq_vector(irq, cfg, TARGET_CPUS);
         if (err)
@@ -3726,6 +3729,9 @@ int arch_setup_ht_irq(unsigned int irq, struct pci_dev *dev)
         struct irq_cfg *cfg;
         int err;
 
+        if (disable_apic)
+                return -ENXIO;
+
         cfg = irq_cfg(irq);
         err = assign_irq_vector(irq, cfg, TARGET_CPUS);
         if (!err) {
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index bb1a3b1fc87f..31f99ec2e0fd 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1125,6 +1125,7 @@ static int __init smp_sanity_check(unsigned max_cpus)
                 printk(KERN_ERR "... forcing use of dummy APIC emulation."
                                 "(tell your hw vendor)\n");
                 smpboot_clear_io_apic();
+                disable_ioapic_setup();
                 return -1;
         }